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authorJoe Thornber <ejt@redhat.com>2013-10-16 10:59:26 +0100
committerMike Snitzer <snitzer@redhat.com>2013-11-11 11:37:49 -0500
commit53d498198d3e8bce4287112beafc30befcba98cc (patch)
treea12f0184d3a5505eca616e32c9b27be551f90070 /drivers/md
parent2ee57d587357f0d752af6c2e3e46434a74b1bee3 (diff)
dm cache metadata: check the metadata version when reading the superblock
Need to check the version to verify on-disk metadata is supported. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-cache-metadata.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 8601425436c..9ef0752e8a0 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -20,7 +20,13 @@
#define CACHE_SUPERBLOCK_MAGIC 06142003
#define CACHE_SUPERBLOCK_LOCATION 0
-#define CACHE_VERSION 1
+
+/*
+ * defines a range of metadata versions that this module can handle.
+ */
+#define MIN_CACHE_VERSION 1
+#define MAX_CACHE_VERSION 1
+
#define CACHE_METADATA_CACHE_SIZE 64
/*
@@ -134,6 +140,18 @@ static void sb_prepare_for_write(struct dm_block_validator *v,
SUPERBLOCK_CSUM_XOR));
}
+static int check_metadata_version(struct cache_disk_superblock *disk_super)
+{
+ uint32_t metadata_version = le32_to_cpu(disk_super->version);
+ if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
+ DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
+ metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int sb_check(struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
@@ -164,7 +182,7 @@ static int sb_check(struct dm_block_validator *v,
return -EILSEQ;
}
- return 0;
+ return check_metadata_version(disk_super);
}
static struct dm_block_validator sb_validator = {
@@ -270,7 +288,7 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
disk_super->flags = 0;
memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
- disk_super->version = cpu_to_le32(CACHE_VERSION);
+ disk_super->version = cpu_to_le32(MAX_CACHE_VERSION);
memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
disk_super->policy_hint_size = 0;